Specifically, the present invention relates to a test device for testing circuit units to be tested, which has connecting units for connecting the circuit units to be tested to the test device and a test system, which writes test data to the circuit units to be tested and reads out measurement data generated by the circuit units to be tested in a manner dependent on the test data written in, the measurement data read out being compared with defined expected data in such a way that test result data are provided in a manner dependent on the comparison.
Testing of circuit units to be tested, which may be formed in particular as electronic semiconductor circuits (chips), is associated with rising test costs in conjunction with an increasing test complexity. Such costs depend inter alia on the following factors:
(i) test duration, i.e. time during which the chip or the circuit unit to be tested is tested; and
(ii) number of simultaneously testable chips.
If the number of simultaneously testable chips or circuit units to be tested is increased, test costs can be lowered.
It is disadvantageous that the number of simultaneously testable chips that can be connected to a test system is limited. Circuit units to be tested have connecting units comprising specific tester channels. Each individual tester channel must be connected to the test system. It is disadvantageous that the number of tester channels provided by a test system is limited.
Thus, a number of n connecting units is required for testing n circuit units to be tested. Each of the n connecting units in turn has m tester channels, with the result that a total number of n×m tester channels have to be provided in order that n circuit units to be tested are tested in parallel. Consequently, conventional test systems have the disadvantage that a parallelism when testing the circuit units to be tested in a test device is limited the number of tester channels provided in the test device.
In order to solve this problem, it has been proposed to increase a parallelism when testing circuit units to be tested by a procedure in which driver lines of different circuit units to be tested are used simultaneously. This is possible since signals are transmitted on the driver lines only from the test system of the test device to the circuit unit to be tested. This is possible in particular when the signals on the driver lines have an identical function.